PROJECT SUMMARY Chronic symptomatic skin diseases are striking examples of common conditions for which patients' reports are crucial outcomes. These diseases only rarely affect conventional vital signs of health such as body temperature and blood pressure, but often affect symptoms and quality of life, features we have called the ?Skin Vital Signs? because they provide a snapshot of fundamental aspects of the patient's skin-related health. The most common skin symptom is itch, a disturbing experience that affects 10-20% of persons, and can be chronic and disabling. Itch is associated with poor well-being, including depressed mood, anxiety, and diminished quality of sleep. A comprehensive understanding of the experience of patients with itch is crucial to monitor the effects of therapies in clinical trials and to inform care decisions. But although survey instruments have been developed to measure itch, none is accepted as the universal standard. Validated measures of patients' reports have long been available, but the measurement of patient's reports has been hampered by burdensome paper-based surveys, inefficient mechanisms for rapid communication of scores, and insufficient information about how to interpret them. A challenge for clinical trials to improve itch, and the care of patients with itch, is the lack of a standardized user-friendly tool to monitor itch and its effects comprehensively, and in ways that clinicians and researchers can easily receive and interpret. The long-term objective of this research is to improve treatment options for patients with itch through the performance of rigorous clinical trials of interventions. We have developed an internet-based tool?called the e-Skin Vital Signs?to measure and communicate in real-time and in interpretable ways patients' reports about their skin symptoms and effects on their quality of life. Our goals are to refine this mobile tool for itch (the ?e-Itch Vital Signs?) based on empirically gathered data from patients and clinicians, and to establish its essential measurement properties and interpretability so that it will be ready for immediate use as an outcomes measure in clinical trials. We will develop and refine the mobile e-Itch Vital Signs, using input from patients and clinicians (Aim 1), and will determine its reliability, validity and responsiveness to changes over time in patients with chronic itch (Aim 2). In a prospective cohort study of patients with chronic itch from atopic dermatitis, we will determine the minimal important difference in e-Itch Vital Signs scores, using a patient-based anchor (Aim 3). This research will provide an accurate, user-friendly, and interpretable measure of itch and its effects for immediate use in clinical trials. This project will generate sufficient data for us to submit the e-Itch Vital Signs tool to the FDA's Clinical Outcome Assessment Qualification Program for qualification as a patient-reported outcome measure for effectiveness determination in clinical trials of interventions to improve itch.